package com.liu.filter;

import com.alibaba.fastjson.JSON;
import com.liu.vo.DataView;
import com.sun.prism.impl.BaseContext;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * 检查用户是否已经登录
 */
@WebFilter(filterName = "LoginCheckFilter",urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    DataView dataView = new DataView();
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest httpServletRequest =(HttpServletRequest) request;
        HttpServletResponse httpServletResponse = (HttpServletResponse) response;

        //1、获取本次请求的URI
        //2、判断本次请求是否需要处理
        //3、如果不需要处理，则直接放行
        //4、判断登录状态，如果已登录，则直接放行
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据,具体响应什么数据，看前端的需求，然后前端会根据登陆状态做页面跳转

        //1、获取本次请求的URI
        String requestURL = httpServletRequest.getRequestURI();

        log.info("拦截到请求: {}", requestURL);

        //定义不需要处理的请求路径
        String[] urls = new String[]{
                "/employee/login",
                "/employee/logout",
                "/backend/**",
                "front/**",
                "/common/**"
        };

        //2、判断本次请求是否需要处理
        boolean check = check(urls, requestURL);

        //3、如果不需要处理，则直接放行
        if(check){
            log.info("本次请求{}不需要处理",requestURL);
            chain.doFilter(httpServletRequest,httpServletResponse);
            return;
        }

        //4、判断登录状态，如果已登录，则直接放行
        if(httpServletRequest.getSession().getAttribute("employee")!=null){
            log.info("用户名已登录，用户id为: {}",httpServletRequest.getSession().getAttribute("employee"));

            Long empId = (Long) httpServletRequest.getSession().getAttribute("employee");

            chain.doFilter(httpServletRequest,httpServletResponse);
            return;
        }

        log.info("用户未登录");
        //5、如果未登录则返回未登录结果，通过输出流方式向客户端页面响应数据,具体响应什么数据，看前端的需求，然后前端会根据登陆状态做页面跳转
        httpServletResponse.getWriter();
        return;
    }

    /**
     * 路径匹配，检查本次请求是否需要放行
     * @param urls
     * @param requestURL
     * @return
     */
    public boolean check(String[] urls,String requestURL){
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURL);
            if(match){
                return true;
            }
        }
        return false;
    }
}
